Luminaires typically incorporate different materials for optical and structural functions. For example, a luminaire might utilize a sheet of polymeric material for a diffuser and a metal material for a frame. Such materials typically have significantly different thermal expansion properties. For example, most polymers may expand and contract significantly more over a given temperature range than most metals. If the luminaire is made so that the different-material components fit snugly against one another at a given temperature, then when the temperature rises, some of the components may buckle due to expansion stress. And when the temperature falls, gaps that are unsightly or that leak light may open.
Accordingly, there is a need in the art for a technology that can address differing expansion properties of components in a luminaire. Need also exists for technology that can provide thermal expansion space in a luminaire. Further need exists for technology to cover thermal expansion gaps in a luminaire. Need further exists for technology to facilitate service access to internal elements of a luminaire that incorporates components having differing thermal expansion properties. A capability addressing one or more such needs, or some other related deficiency in the art, would support improved illumination and improved illumination systems.